Process of inhibiting the degradation of photographic color images



Patented Dec. 18, 1951 PROCESS OF INHIBI'IIING THE DEGR-ADA-V TION'OF PHOTOGRAPHIC COLOR IMAGES E. Scudder Mackey,v Binghamton, N. Y., assignor to General Aniline & Film Corporation, New York, N. Y., a corporation of Delaware No; Drawing. Application April 12, 1950,

' Serial No. 155,558

(s-claim; (01. 95-88) This invent'ion relates tothetreatment. of color photographs and especially to, final rinse. baths ior inhibiting? the color decomposition or azo; a'zine. azomethine, indophenol, and. quinonim-ine dyes presentin color, photographic emulsions. I

I Despite. the ordinary precautions; taken in storing color. photographs; and prints. the color balanceis often altered by heat, extreme humidity conditions. and residual processing chemicals. This lack of color stability is veryundesirable. as. valuable color records are rendered useless. The deterioration occurs asayellowing. or brown.- ing of the color photograph, if storage is in a heated atmosphere, Another photographic dye fading. condition. often results in the lossv of yellow or. other color dyesrv condition is caused by high. temperature and highhumidityc For. in:- stance, the storing of; colored photographs in an attic or even in a. wallet often produces this. undesirable color deteriorationc It has, been; determined that. color prints, particularly the white, will. stain a brown because oi. oxidation of. the color developing, agent-retained in. the subbing layer and in. dye clumps. processed without the color development, step do not exhibit this stain. These undesirable eifects are frequently observed in the color photographs, containing; azomethine dyes. The changes naturally restrict. the storage. conditions. while methods of increasing theresistanceof these dyes to extreme humid-ityand residual chemical fading. are of great commercial importance. Anobject of my invention. is to. provide a novel method, of treating-colored photographs" so that extreme humidity conditions. do not destroy the original coloration .Another object of. my. invention.v is to.- obtain color photographs whose, colors are stable to heat as well as to the deteriorating effect. of residual color developing chemicals. v 7

Otherobjects and advantages will become apparent as the description proceeds.

I have found that the above objects areaccomplished by employing-as a, final rinse bath an aqueous solution containing astain inhibiting amount of a. water-soluble hydantoin 'comcharacterized by the following-1- general formulae: I a I R HC \C=O Jon, N'\ I z: c c;-=o tel wherein R re'presents' either-hydrogen or methylol (J-CI-IzOH) group. Rrrepresentsa lower alkyl group, e. g., methyLethylipropyl, isopropyl etc., R2 represents a. lower alkyl. group of the same values as R1 or lower alkoxyalkyl' group, e. g;., methoxymethyl', ethoxyethyl, propoxypropyl-,. etc., R3 represents either hydrogen or lower alkyl group of the same-value as; in; R2,, and, 2- represents-thedival'ent methylene radicals necessary to complete a 5- or; 6-membered cycloaliphatic group, such: as cyclopentyl; or cyclohexyl and, the water-soluble formaldehyde addition products of said hydantoin compound;

The following: are; examples of suitable hydantoins which may be employed forthepurpose herein. set forth:

1 (-or 3:) -metliylol*.i-methylhydantoinand itswater-soluble polymers o ogl o= -N- omorc 1 (or 3) -methylol-5,fi-dimethylhydantoin The water-soluble resinous addition products of formaldehyde and hydantoins are readily prepared according to the process described in United States Patent 2,155,863, which discloses examples of such compounds contemplated for use herein.

This finding makes it possible to render color developed multicolor photographic material practically immune to the deteriorative effects of storage or aging while unafiecting the original color balance.- The extreme humidity fading characteristics of developing multicolor photographic materials containing azo, azine, azomethine, i'n'dophenol, and quinonimine dyes are substantially improved by subjecting the processed color photographs or transparencies to treatment with aqueous solutions of said hydantoins. When such solutions are employed as final rinse baths, 1. e., after the complete processing of multicolor material, they will inhibit the color loss of color photographs which have. been exposed to extreme humidity conditions, accelerated aging, or acid vapors when effecting the original color balance. J

The concentration of the hydantoin compound may be varied from as little as .5% to as much as 20%. Amounts higher than the latterv give little improvement. Concentrations ranging between 2 and yield satisfactory results. The time of rinsing may also vary between 1 to minutes. However, best results with a 3% solution are obtained when the bathing of the processed film is'from 3 to 5' minutes. In developing solutions, the hydantoin compounds may be employed in acid, neutral, or alkaline media. Solutions having a pH of about 8 are, however, preferred.

The photographic multicolor materials, which may be processed with the anti-stain bath of the present invention are color reversible film, color negative film, color reversible white printing ma terial coated on an opaque base, and color positive printing material coated on paper, irrespective of whether the dyestuff images are produced with color formers present in the emulsion, or by a selective second exposure-followed by development with developing solutions containing color formers and color developing agents.

The color reversible film consists of an integral tri-pack emulsion coated .on the usual clear cellulose acetate or nitrate film base. Each of the emulsions is sensitized to one of the primary colors of light; namely,'b1ue, green, "and red. The

. color formers in which case the film is processed 4 top layer is blue sensitiven A filter layer, yellow in color and blue absorbing, lies under the top layer. Below this filter layer, lies a green sensitive emulsion layer, and below thisis a red sensitive emulsion layer.: Each of the three silver halide emulsion layers contains dye forming compounds which unite during the development of a silver image in an aromatic amine developing agent to form a dye with the oxidation product of the developing agent, or may be free from with the color formers in the color developers by the selective second ex os re and color development method as described in United States Patents 1.897.866. 1.900.870. 1,928,709, and 1.980941.

I As silver is formed during development, it must be removed after color development by treatment in a bleach, followed by treatment in a bath of sodium thiosulfate. accordin to usual practice. A yellow d e is formed'inthe blue sensitive emulsion; a ma enta dye is formed in the green sensi-v tive em lsion; anda cyan d e is formed in the red sensiti e emulsion. Combinations oi these three printing primaries will produce all of the other colors in the finished film or print.

The color negative film is made up in the same manner as the color reversible film with the excention that it may contain a layer of clear gelatin between the red sensitive layer and the green sensitive layer. The color reversible white opaoue material. is prepared in the same manner as color reversible film and the color negative film with the exce tion that the base consists of an o aoue white film. The color pa er is also constructed in the same'manner as the color reversible film and the color ne ative film, with the exception that the emulsion is coated on a baryta coated a er base. Suitable methods for the preparation of photogra hic multilayer materials have been described in the literature relating to color photography and are, therefore, not described here.

, Multicolor photogra hic materials which are color develo ed by azine developers, 1. e., aromatic triamines, to yield azine (phenazonium) dye images are described in United States Patent 2,486,440. V

Multicolor photograph c materials in which the final dye images areazo dye images areprepared according to the procedural steps disclosed in United States Patents 1,985.344 and 2,020,775.

, The following examples describe in detail the methods for accomplishing the above objects, but it is to be understood that they are inserted merely for the purpose of illustration and are not to be construed as limiting the scope of the invention.

Example I A 2%" x 2%" color transparency was printed by projection on two 3" x 5" sheets of color reversible white opaque film having gelatin layers on both sides of the film base. The two exposed color reversible white opaque film sheets were first developed for 12'minutesat 68 F. in a developer of the following composition:

p-Monomethylaminophenol sulfategrams 3 Sodium sulfite do 50 Hydroquinone do 6 Sodium carbonate; .(m'onohydrate) do 40 Sodium thiocyanate do 2 Potassium bromide do 2 Water to make liters 1 'The developed filmxwas 's'hortstoppedior 3 minutes at 68 in a 5% aqueous solution of sodium b'isulphate; T I A f Thefil m was washed icr z minut'es in running water at 68" F. andre-exposed to white light;

The re-ex-posed film wastizol'ordeveloped for 15 minutes at 68 F. in a developer of the fbllowing composition: I p-Aminodiethylaniline monohydrochloride:

I gramsi e Sodium su1nte do 20 Hydroxylamine;hydrochloride do 2 Sodium carbonate do 80 Potassium bromide do 1 Water to make liters 1 The color developed film was rinsed for 4 minutes in running water at 68 F. and hardened for 5 minutes in a 3% aqueous solution of potassium chrome alum.

The hardened film was washed for 5 minutes in running water at 68 F. The washed material was then treated with a bleach bath of the following composition:

Dipotassium monosodium ferricyanide grams 100 Potassium bromide do 15 Disodium phosphate do 40 Sodium bisulfate do; 25 Formalin (40%) cubic centimeters 20 Water to make liters 1 The bleached film was washed for 5 minutes at 68 F. and then fixed for 5 minutes in a solution of the following composition:

Hypo grams 200 Borax do Water to make liters 1 brown-yellowln the white areas: browniyellow "stain was very' noticeable on the back: of

the-untreated print. The images? on the treated print had not yellowed nor: 'did the back or. the print. show the yellow-brown stain. which was "so noticeable on the untreated print. I

e .Emm zem, V Exampler-Ilwas repeated witha'the exception that parts by weight of 5,5'.-dime.thylhydantoin. formaldehyde re'sirrfw'as replaced by the ysame weight 05 1- methylolii- 5 5:- dimethylhydantoin.

The ;1mtreated.print,- after being subjected to. the

high humidityoven: test was completely ruined whereas the treated print showed no noticeable discoloration.

Example IV Example I was repeated with the exception that the final rinse bath was a slightly alkaline 3% solution of fi-methylhydantoin instead of a 2% solution of 5,5-dimethylhydantoin-formaldehyde resin. The untreated film, after being subjected Both prints, i. e., the treated and untreated,

were exposed to high humidity oven conditions for 5 hours. During this time, the relative humidity in the oven ranged progressively from 56 to 100% at a temperature rangin from 40 to 60 C. The prints were removed from the oven and allowed to reach room temperature. It was observed that a very slight yellowing appeared on the treated color print. The color balance of the untreated color print, however, was completely ruined by a yellow stain appearing overall while at the same time the densities of the original yellow image were lowered. It was also noted that theback of the treated print was free of the yellow-brown stain which hadappeared on the untreated sample.

Example II Example I was repeated with the exception that the high humidity oven test was replaced by a storage test. Both prints, 1. e., the treated and untreated, were stored in an ordinary filing cabinet for over 8 months. Upon inspection, it was noted that the untreated print had stained a to the high humidity oven test, showed an overall yellow stain and as a result the color balance was completely ruined, whereas the treated film showed no staining whatsoever.

The above specific examples are to be regarded as being merely illustrative of the invention and not in any sense restrictive. It will be obvious to those skilled in the art that many modifications, such as substituting equivalent materials and varying the proportions of the materials used, may be made. The scope of the invention is to be limited solely by the appended claims.

I claim:

1. In the process of producing color photographic images in a multicolor photographic emulsion by exposing the emulsion, color developing, bleaching, fixing and washing the same, the improvement which comprises preventing the formation of stain after the washing operation by rinsing the said colored picture with an aqueous solution containing, in an anti-staining amount, a hydantoin compound selected from the class consisting of those corresponding to the following formulae:

7 wherein It represents a member selected from the class consisting of hydrogen and methylcl group. R1 represents a lower alkyl group, R2 is a group selected from the class consisting of lower alkyl and lower alkoxyalkyl groups, R3 represents a 5 member selected from the class consisting of hydrogen and lower alkyl group, Z represents the methylene radicals necessary to complete a member selected from the class consisting of fivemembered and six -membered cycloaliphetic :groups, and the water-solubleformaldehyde addition products of said hydantoin compound.

2. The process according to claim 1 wherein the hydantoin compound is 5-ethylhydantoin.

hydantoin compound is 1-methyl0l-5,5-dimethyl'- hydantoin. s a

6. The process according to claim 1 'whereinthe hydant oin compound is fij-dimethylhydantoin;

10 formaldehyde resin.

E. SCUDDER MACKEY; i.

' No references cited.' 

1. IN THE PROCESS OF PRODUCING COLOR PHOTOGRAPHIC IMAGES IN A MULTICOLOR PHOTOGRAPHIC EMULSION BY EXPOSING THE EMULSION, COLOR DEVELOPING, BLEACHING, FIXING AND WASHING THE SAME, THE IMPROVEMENT WHICH COMPRISES PREVENTING THE FORMATION OF STAIN AFTER THE WASHING OPERATION BY RINSING THE SAID COLORED PICTURE WITH AN AQUEOUS SOLUTION CONTAINING,IN AN ANTI-STAINING AMOUNT, A HYDANTOIN COMPOUND SELECTED FROM THE CLASS CONSISTING OF THOSE CORRESPONDING TO THE FOLLOWING FORMULAE: 